improving error handling

lib/navbar.dart

@@ -15,7 +15,6 @@ class ScaffoldWithNavBar extends StatefulWidget {
 }
 
 class _ScaffoldWithNavBarState extends State<ScaffoldWithNavBar> {
-  bool _isLoggedIn = false;
   late String initials;
 
   @override
@@ -29,7 +28,6 @@ class _ScaffoldWithNavBarState extends State<ScaffoldWithNavBar> {
 
     if (prefs.getString("token") != null) {
       setState(() {
-        _isLoggedIn = true;
         initials = prefs.getString("initials")!;
       });
     }
@@ -56,7 +54,7 @@ class _ScaffoldWithNavBarState extends State<ScaffoldWithNavBar> {
                               child: Padding(
                                 padding: const EdgeInsets.symmetric(
                                   vertical: 12.0,
-                                  horizontal: 8
+                                  horizontal: 8,
                                 ),
                                 child: Image(
                                   image: AssetImage('assets/velocity.png'),
@@ -186,7 +184,10 @@ class _ScaffoldWithNavBarState extends State<ScaffoldWithNavBar> {
     final String location = GoRouterState.of(context).uri.path;
     if (location.startsWith('/groups')) return 1;
     if (location.startsWith('/history')) return 2;
-    if (location.startsWith('/more') || location.startsWith('/users') || location.startsWith('/uptime')) return 3;
+    if (location.startsWith('/more') ||
+        location.startsWith('/users') ||
+        location.startsWith('/uptime'))
+      return 3;
     return 0;
   }